Othman Mahmoud, interior minister of the Kurdish regional government in the north, said shelling was going on along the border about 170 km (105 miles) north of the city of Sulaimaniya.
Militants from minority Kurdish groups from Iran and Turkey have based themselves in northern Iraq.
Mahmoud said it was still not clear whether there were any casualties.
“We in the regional Kurdish government condemn this act which is a violation of international law,” said Mahmoud.
There was no immediate comment from officials in Iran.
Kurdish officials have previously accused Iranian forces of shelling Iranian Kurds based in Iraq.
